Stanley Lee Abstract Type B 2024

Hematopoiesis is the continuous process of blood cell production sustained by a rare population of hematopoietic stem cells (HSCs) that reside in the adult bone marrow. HSCs possess the ability to both self-renew and undergo lineage-restricted differentiation upon receiving cues from the microenvironment. To date, most of the studies have focused on the roles of transcription factors and chromatin regulators and how they modulate gene expression programs during hematopoietic differentiation. The role of post-transcriptional pathways has gained significant attention following the discovery that splicing factors are frequent targets of somatic mutations in in age-related blood disorders such as clonal hematopoiesis (CH) and myelodysplastic syndromes (MDS). These discoveries suggest that RNA splicing regulation is a key determinant of hematopoietic homeostasis and pathology. Moreover, we currently do not understand the full repertoire of mRNA isoforms and their functionality in lineage commitment and differentiation, and the identity of pathologic isoforms that drive CH and MDS. In this proposal, we aim to leverage novel sequencing and computational approaches to capture global splicing alterations in normal and dysplastic hematopoiesis. Additionally, we will validate the functionality of newly discovered isoforms using high-throughput assays. Successful completion of this pilot study will provide critical insight on how aberrant isoform usage and heterogeneity fuels the decline of HSC function in age-related blood disorders.